1 /* general.c -- Stuff that is used by all files. */
3 /* Copyright (C) 1987-2004 Free Software Foundation, Inc.
5 This file is part of GNU Bash, the Bourne Again SHell.
7 Bash is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 Bash is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License along
18 with Bash; see the file COPYING. If not, write to the Free Software
19 Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
23 #include "bashtypes.h"
25 # include <sys/param.h>
27 #include "posixstat.h"
29 #if defined (HAVE_UNISTD_H)
36 #include "chartypes.h"
44 #include <tilde/tilde.h>
50 extern int expand_aliases;
51 extern int interrupt_immediately;
52 extern int interactive_comments;
53 extern int check_hashed_filenames;
54 extern int source_uses_path;
55 extern int source_searches_cwd;
57 static char *bash_special_tilde_expansions __P((char *));
58 static int unquoted_tilde_word __P((const char *));
59 static void initialize_group_array __P((void));
61 /* A standard error message to use when getcwd() returns NULL. */
62 char *bash_getcwd_errstr = N_("getcwd: cannot access parent directories");
64 /* Do whatever is necessary to initialize `Posix mode'. */
69 /* Things that should be turned on when posix mode is enabled. */
72 interactive_comments = source_uses_path = expand_aliases = 1;
75 /* Things that should be turned on when posix mode is disabled. */
78 source_searches_cwd = 1;
79 expand_aliases = interactive_shell;
83 /* **************************************************************** */
85 /* Functions to convert to and from and display non-standard types */
87 /* **************************************************************** */
89 #if defined (RLIMTYPE)
91 string_to_rlimtype (s)
99 while (s && *s && whitespace (*s))
101 if (*s == '-' || *s == '+')
106 for ( ; s && *s && DIGIT (*s); s++)
107 ret = (ret * 10) + TODIGIT (*s);
108 return (neg ? -ret : ret);
112 print_rlimtype (n, addnl)
116 char s[INT_STRLEN_BOUND (RLIMTYPE) + 1], *p;
125 while ((n /= 10) != 0);
133 while ((n /= 10) != 0);
136 printf ("%s%s", p, addnl ? "\n" : "");
138 #endif /* RLIMTYPE */
140 /* **************************************************************** */
142 /* Input Validation Functions */
144 /* **************************************************************** */
146 /* Return non-zero if all of the characters in STRING are digits. */
153 for (s = string; *s; s++)
160 /* Return non-zero if the characters pointed to by STRING constitute a
161 valid number. Stuff the converted number into RESULT if RESULT is
164 legal_number (string, result)
175 value = strtoimax (string, &ep, 10);
177 return 0; /* errno is set on overflow or underflow */
179 /* Skip any trailing whitespace, since strtoimax does not. */
180 while (whitespace (*ep))
183 /* If *string is not '\0' but *ep is '\0' on return, the entire string
185 if (string && *string && *ep == '\0')
189 /* The SunOS4 implementation of strtol() will happily ignore
190 overflow conditions, so this cannot do overflow correctly
198 /* Return 1 if this token is a legal shell `identifier'; that is, it consists
199 solely of letters, digits, and underscores, and does not begin with a
202 legal_identifier (name)
208 if (!name || !(c = *name) || (legal_variable_starter (c) == 0))
211 for (s = name + 1; (c = *s) != 0; s++)
213 if (legal_variable_char (c) == 0)
219 /* Make sure that WORD is a valid shell identifier, i.e.
220 does not contain a dollar sign, nor is quoted in any way. Nor
221 does it consist of all digits. If CHECK_WORD is non-zero,
222 the word is checked to ensure that it consists of only letters,
223 digits, and underscores. */
225 check_identifier (word, check_word)
229 if ((word->flags & (W_HASDOLLAR|W_QUOTED)) || all_digits (word->word))
231 internal_error (_("`%s': not a valid identifier"), word->word);
234 else if (check_word && legal_identifier (word->word) == 0)
236 internal_error (_("`%s': not a valid identifier"), word->word);
243 /* Return 1 if STRING comprises a valid alias name. The shell accepts
244 essentially all characters except those which must be quoted to the
245 parser (which disqualifies them from alias expansion anyway) and `/'. */
247 legal_alias_name (string, flags)
253 for (s = string; *s; s++)
254 if (shellbreak (*s) || shellxquote (*s) || shellexp (*s) || (*s == '/'))
259 /* Returns non-zero if STRING is an assignment statement. The returned value
260 is the index of the `=' sign. */
262 assignment (string, flags)
266 register unsigned char c;
267 register int newi, indx;
269 c = string[indx = 0];
271 #if defined (ARRAY_VARS)
272 if ((legal_variable_starter (c) == 0) && (flags == 0 || c != '[')) /* ] */
274 if (legal_variable_starter (c) == 0)
278 while (c = string[indx])
280 /* The following is safe. Note that '=' at the start of a word
281 is not an assignment statement. */
285 #if defined (ARRAY_VARS)
288 newi = skipsubscript (string, indx);
289 if (string[newi++] != ']')
291 if (string[newi] == '+' && string[newi+1] == '=')
293 return ((string[newi] == '=') ? newi : 0);
295 #endif /* ARRAY_VARS */
298 if (c == '+' && string[indx+1] == '=')
301 /* Variable names in assignment statements may contain only letters,
303 if (legal_variable_char (c) == 0)
311 /* **************************************************************** */
313 /* Functions to manage files and file descriptors */
315 /* **************************************************************** */
317 /* A function to unset no-delay mode on a file descriptor. Used in shell.c
318 to unset it on the fd passed as stdin. Should be called on stdin if
319 readline gets an EAGAIN or EWOULDBLOCK when trying to read input. */
321 #if !defined (O_NDELAY)
322 # if defined (FNDELAY)
323 # define O_NDELAY FNDELAY
325 #endif /* O_NDELAY */
327 /* Make sure no-delay mode is not set on file descriptor FD. */
329 sh_unset_nodelay_mode (fd)
334 if ((flags = fcntl (fd, F_GETFL, 0)) < 0)
339 /* This is defined to O_NDELAY in filecntl.h if O_NONBLOCK is not present
340 and O_NDELAY is defined. */
342 bflags |= O_NONBLOCK;
352 return (fcntl (fd, F_SETFL, flags));
358 /* Return 1 if file descriptor FD is valid; 0 otherwise. */
363 return (fcntl (fd, F_GETFD, 0) >= 0);
366 /* There is a bug in the NeXT 2.1 rlogind that causes opens
367 of /dev/tty to fail. */
369 #if defined (__BEOS__)
370 /* On BeOS, opening in non-blocking mode exposes a bug in BeOS, so turn it
371 into a no-op. This should probably go away in the future. */
373 # define O_NONBLOCK 0
374 #endif /* __BEOS__ */
382 tty_fd = open ("/dev/tty", O_RDWR|O_NONBLOCK);
386 tty = (char *)ttyname (fileno (stdin));
389 tty_fd = open (tty, O_RDWR|O_NONBLOCK);
394 /* Return 1 if PATH1 and PATH2 are the same file. This is kind of
395 expensive. If non-NULL STP1 and STP2 point to stat structures
396 corresponding to PATH1 and PATH2, respectively. */
398 same_file (path1, path2, stp1, stp2)
400 struct stat *stp1, *stp2;
402 struct stat st1, st2;
406 if (stat (path1, &st1) != 0)
413 if (stat (path2, &st2) != 0)
418 return ((stp1->st_dev == stp2->st_dev) && (stp1->st_ino == stp2->st_ino));
421 /* Move FD to a number close to the maximum number of file descriptors
422 allowed in the shell process, to avoid the user stepping on it with
423 redirection and causing us extra work. If CHECK_NEW is non-zero,
424 we check whether or not the file descriptors are in use before
425 duplicating FD onto them. MAXFD says where to start checking the
426 file descriptors. If it's less than 20, we get the maximum value
427 available from getdtablesize(2). */
429 move_to_high_fd (fd, check_new, maxfd)
430 int fd, check_new, maxfd;
432 int script_fd, nfds, ignore;
436 nfds = getdtablesize ();
439 if (nfds > HIGH_FD_MAX)
440 nfds = HIGH_FD_MAX; /* reasonable maximum */
445 for (nfds--; check_new && nfds > 3; nfds--)
446 if (fcntl (nfds, F_GETFD, &ignore) == -1)
449 if (nfds > 3 && fd != nfds && (script_fd = dup2 (fd, nfds)) != -1)
451 if (check_new == 0 || fd != fileno (stderr)) /* don't close stderr */
456 /* OK, we didn't find one less than our artificial maximum; return the
457 original file descriptor. */
461 /* Return non-zero if the characters from SAMPLE are not all valid
462 characters to be found in the first line of a shell script. We
463 check up to the first newline, or SAMPLE_LEN, whichever comes first.
464 All of the characters must be printable or whitespace. */
467 check_binary_file (sample, sample_len)
474 for (i = 0; i < sample_len; i++)
480 if (ISSPACE (c) == 0 && ISPRINT (c) == 0)
487 /* **************************************************************** */
489 /* Functions to inspect pathnames */
491 /* **************************************************************** */
499 return ((stat (fn, &sb) == 0) && S_ISDIR (sb.st_mode));
506 return (file_isdir (fn) && test_eaccess (fn, W_OK) == 0);
509 /* Return 1 if STRING contains an absolute pathname, else 0. Used by `cd'
510 to decide whether or not to look up a directory name in $CDPATH. */
512 absolute_pathname (string)
515 if (string == 0 || *string == '\0')
521 if (string[0] == '.' && PATHSEP(string[1])) /* . and ./ */
524 if (string[0] == '.' && string[1] == '.' && PATHSEP(string[2])) /* .. and ../ */
530 /* Return 1 if STRING is an absolute program name; it is absolute if it
531 contains any slashes. This is used to decide whether or not to look
534 absolute_program (string)
537 return ((char *)xstrchr (string, '/') != (char *)NULL);
540 /* **************************************************************** */
542 /* Functions to manipulate pathnames */
544 /* **************************************************************** */
546 /* Turn STRING (a pathname) into an absolute pathname, assuming that
547 DOT_PATH contains the symbolic location of `.'. This always
548 returns a new string, even if STRING was an absolute pathname to
551 make_absolute (string, dot_path)
552 char *string, *dot_path;
556 if (dot_path == 0 || ABSPATH(string))
559 char pathbuf[PATH_MAX + 1];
561 cygwin_conv_to_full_posix_path (string, pathbuf);
562 result = savestring (pathbuf);
565 result = savestring (string);
568 result = sh_makepath (dot_path, string, 0);
573 /* Return the `basename' of the pathname in STRING (the stuff after the
574 last '/'). If STRING is `/', just return it. */
576 base_pathname (string)
582 if (absolute_pathname (string) == 0)
586 if (string[0] == '/' && string[1] == 0)
589 p = (char *)strrchr (string, '/');
590 return (p ? ++p : string);
593 /* Return the full pathname of FILE. Easy. Filenames that begin
594 with a '/' are returned as themselves. Other filenames have
595 the current working directory prepended. A new string is
596 returned in either case. */
603 file = (*file == '~') ? bash_tilde_expand (file, 0) : savestring (file);
608 ret = sh_makepath ((char *)NULL, file, (MP_DOCWD|MP_RMDOT));
614 /* A slightly related function. Get the prettiest name of this
615 directory possible. */
616 static char tdir[PATH_MAX];
618 /* Return a pretty pathname. If the first part of the pathname is
619 the same as $HOME, then replace that with `~'. */
621 polite_directory_format (name)
627 home = get_string_value ("HOME");
628 l = home ? strlen (home) : 0;
629 if (l > 1 && strncmp (home, name, l) == 0 && (!name[l] || name[l] == '/'))
631 strncpy (tdir + 1, name + l, sizeof(tdir) - 2);
633 tdir[sizeof(tdir) - 1] = '\0';
640 /* Given a string containing units of information separated by colons,
641 return the next one pointed to by (P_INDEX), or NULL if there are no more.
642 Advance (P_INDEX) to the character after the colon. */
644 extract_colon_unit (string, p_index)
654 len = strlen (string);
656 return ((char *)NULL);
660 /* Each call to this routine leaves the index pointing at a colon if
661 there is more to the path. If I is > 0, then increment past the
662 `:'. If I is 0, then the path has a leading colon. Trailing colons
663 are handled OK by the `else' part of the if statement; an empty
664 string is returned in that case. */
665 if (i && string[i] == ':')
668 for (start = i; string[i] && string[i] != ':'; i++)
677 /* Return "" in the case of a trailing `:'. */
678 value = (char *)xmalloc (1);
682 value = substring (string, start, i);
687 /* **************************************************************** */
689 /* Tilde Initialization and Expansion */
691 /* **************************************************************** */
693 #if defined (PUSHD_AND_POPD)
694 extern char *get_dirstack_from_string __P((char *));
697 static char **bash_tilde_prefixes;
698 static char **bash_tilde_prefixes2;
699 static char **bash_tilde_suffixes;
700 static char **bash_tilde_suffixes2;
702 /* If tilde_expand hasn't been able to expand the text, perhaps it
703 is a special shell expansion. This function is installed as the
704 tilde_expansion_preexpansion_hook. It knows how to expand ~- and ~+.
705 If PUSHD_AND_POPD is defined, ~[+-]N expands to directories from the
708 bash_special_tilde_expansions (text)
713 result = (char *)NULL;
715 if (text[0] == '+' && text[1] == '\0')
716 result = get_string_value ("PWD");
717 else if (text[0] == '-' && text[1] == '\0')
718 result = get_string_value ("OLDPWD");
719 #if defined (PUSHD_AND_POPD)
720 else if (DIGIT (*text) || ((*text == '+' || *text == '-') && DIGIT (text[1])))
721 result = get_dirstack_from_string (text);
724 return (result ? savestring (result) : (char *)NULL);
727 /* Initialize the tilde expander. In Bash, we handle `~-' and `~+', as
728 well as handling special tilde prefixes; `:~" and `=~' are indications
729 that we should do tilde expansion. */
733 static int times_called = 0;
735 /* Tell the tilde expander that we want a crack first. */
736 tilde_expansion_preexpansion_hook = bash_special_tilde_expansions;
738 /* Tell the tilde expander about special strings which start a tilde
739 expansion, and the special strings that end one. Only do this once.
740 tilde_initialize () is called from within bashline_reinitialize (). */
741 if (times_called++ == 0)
743 bash_tilde_prefixes = strvec_create (3);
744 bash_tilde_prefixes[0] = "=~";
745 bash_tilde_prefixes[1] = ":~";
746 bash_tilde_prefixes[2] = (char *)NULL;
748 bash_tilde_prefixes2 = strvec_create (2);
749 bash_tilde_prefixes2[0] = ":~";
750 bash_tilde_prefixes2[1] = (char *)NULL;
752 tilde_additional_prefixes = bash_tilde_prefixes;
754 bash_tilde_suffixes = strvec_create (3);
755 bash_tilde_suffixes[0] = ":";
756 bash_tilde_suffixes[1] = "=~"; /* XXX - ?? */
757 bash_tilde_suffixes[2] = (char *)NULL;
759 tilde_additional_suffixes = bash_tilde_suffixes;
761 bash_tilde_suffixes2 = strvec_create (2);
762 bash_tilde_suffixes2[0] = ":";
763 bash_tilde_suffixes2[1] = (char *)NULL;
767 /* POSIX.2, 3.6.1: A tilde-prefix consists of an unquoted tilde character
768 at the beginning of the word, followed by all of the characters preceding
769 the first unquoted slash in the word, or all the characters in the word
770 if there is no slash...If none of the characters in the tilde-prefix are
771 quoted, the characters in the tilde-prefix following the tilde shell be
772 treated as a possible login name. */
774 #define TILDE_END(c) ((c) == '\0' || (c) == '/' || (c) == ':')
777 unquoted_tilde_word (s)
782 for (r = s; TILDE_END(*r) == 0; r++)
795 /* Find the end of the tilde-prefix starting at S, and return the tilde
796 prefix in newly-allocated memory. Return the length of the string in
797 *LENP. FLAGS tells whether or not we're in an assignment context --
798 if so, `:' delimits the end of the tilde prefix as well. */
800 bash_tilde_find_word (s, flags, lenp)
808 for (r = s; *r && *r != '/'; r++)
810 /* Short-circuit immediately if we see a quote character. Even though
811 POSIX says that `the first unquoted slash' (or `:') terminates the
812 tilde-prefix, in practice, any quoted portion of the tilde prefix
813 will cause it to not be expanded. */
814 if (*r == '\\' || *r == '\'' || *r == '"')
816 ret = savestring (s);
821 else if (flags && *r == ':')
825 ret = xmalloc (l + 1);
833 /* Tilde-expand S by running it through the tilde expansion library.
834 ASSIGN_P is 1 if this is a variable assignment, so the alternate
835 tilde prefixes should be enabled (`=~' and `:~', see above). If
836 ASSIGN_P is 2, we are expanding the rhs of an assignment statement,
837 so `=~' is not valid. */
839 bash_tilde_expand (s, assign_p)
846 old_immed = interrupt_immediately;
847 interrupt_immediately = 1;
849 tilde_additional_prefixes = assign_p == 0 ? (char **)0
850 : (assign_p == 2 ? bash_tilde_prefixes2 : bash_tilde_prefixes);
852 tilde_additional_suffixes = bash_tilde_suffixes2;
854 r = (*s == '~') ? unquoted_tilde_word (s) : 1;
855 ret = r ? tilde_expand (s) : savestring (s);
856 interrupt_immediately = old_immed;
860 /* **************************************************************** */
862 /* Functions to manipulate and search the group list */
864 /* **************************************************************** */
866 static int ngroups, maxgroups;
868 /* The set of groups that this user is a member of. */
869 static GETGROUPS_T *group_array = (GETGROUPS_T *)NULL;
871 #if !defined (NOGROUP)
872 # define NOGROUP (gid_t) -1
876 initialize_group_array ()
881 maxgroups = getmaxgroups ();
884 group_array = (GETGROUPS_T *)xrealloc (group_array, maxgroups * sizeof (GETGROUPS_T));
886 #if defined (HAVE_GETGROUPS)
887 ngroups = getgroups (maxgroups, group_array);
890 /* If getgroups returns nothing, or the OS does not support getgroups(),
891 make sure the groups array includes at least the current gid. */
894 group_array[0] = current_user.gid;
898 /* If the primary group is not in the groups array, add it as group_array[0]
899 and shuffle everything else up 1, if there's room. */
900 for (i = 0; i < ngroups; i++)
901 if (current_user.gid == (gid_t)group_array[i])
903 if (i == ngroups && ngroups < maxgroups)
905 for (i = ngroups; i > 0; i--)
906 group_array[i] = group_array[i - 1];
907 group_array[0] = current_user.gid;
911 /* If the primary group is not group_array[0], swap group_array[0] and
912 whatever the current group is. The vast majority of systems should
913 not need this; a notable exception is Linux. */
914 if (group_array[0] != current_user.gid)
916 for (i = 0; i < ngroups; i++)
917 if (group_array[i] == current_user.gid)
921 group_array[i] = group_array[0];
922 group_array[0] = current_user.gid;
927 /* Return non-zero if GID is one that we have in our groups list. */
929 #if defined (__STDC__) || defined ( _MINIX)
930 group_member (gid_t gid)
934 #endif /* !__STDC__ && !_MINIX */
936 #if defined (HAVE_GETGROUPS)
940 /* Short-circuit if possible, maybe saving a call to getgroups(). */
941 if (gid == current_user.gid || gid == current_user.egid)
944 #if defined (HAVE_GETGROUPS)
946 initialize_group_array ();
948 /* In case of error, the user loses. */
952 /* Search through the list looking for GID. */
953 for (i = 0; i < ngroups; i++)
954 if (gid == (gid_t)group_array[i])
965 static char **group_vector = (char **)NULL;
976 initialize_group_array ();
982 return (char **)NULL;
985 group_vector = strvec_create (ngroups);
986 for (i = 0; i < ngroups; i++)
987 group_vector[i] = itos (group_array[i]);
995 get_group_array (ngp)
999 static int *group_iarray = (int *)NULL;
1005 return (group_iarray);
1009 initialize_group_array ();
1018 group_iarray = (int *)xmalloc (ngroups * sizeof (int));
1019 for (i = 0; i < ngroups; i++)
1020 group_iarray[i] = (int)group_array[i];
1024 return group_iarray;